1. Field of the Invention
The present invention relates to an object, a method, or a method for producing an object. In particular, the present invention relates to a display device or a semiconductor device. Specifically, the present invention relates to a display device in which a single-crystal semiconductor is fixed to an insulating substrate.
2. Description of the Related Art
In recent years, a display device in which not only a pixel but also a driver circuit is formed over a glass substrate has been developed. As a pixel, a liquid crystal element, an organic EL element, or the like is used. At this time, a circuit is formed over a glass substrate by using a thin film transistor (TFT) formed of low temperature polysilicon. However, the TFT has worse current characteristics and higher threshold voltage than those of a transistor formed of a single crystal. Therefore, operations are performed with power supply voltage or signal amplitude increased. In order to increase the amplitude, a level shifter circuit or the like is used (for example, see Reference 1: Japanese Published Patent Application No. 2000-259111).